By "class of word" I mean a noun, verb, adjective, adverb etc. This notation came from reading the definitions of these words themselves. For example
noun grammar any member of a class of words that can function as a ...
verb grammar any member of a class of words that function as the main elements of predicates, that typically express action ...
By "not changing form", I mean the noun, adjective, verb etc. forms are spelled (and possibly pronounced) exactly the same. An example that doesn't fit this would be late, which is an adjective and has an adverb form of lately.
I thought of the example word 'complex' last night and wondered if there were a noun that encompasses such words.
com·plex [adj., v. kuhm-pleks, kom-pleks; n. kom-pleks]
adjective 1 - composed of many interconnected parts; compound; composite: a complex highway system.
noun 6 - an intricate or complicated association or assemblage of related things, parts, units, etc.: the entire complex of our educational system; an apartment complex.
And in researching this, I discovered that there is also a verb form of complex specific to chemistry:
verb (used with object) 12 - Chemistry . to form a complex with.
This leads to using a situation where a the word in question can be repeated immediately in a sentence and still be grammatically correct (but admittedly confusing).
My apartment is part of a complex complex.
Interestingly, I found a brain teaser game which fits what I was looking for, providing 24 other examples, but doesn't define things any more precisely. I also found this interesting tutorial covering the case where nouns are used in their exact nounal meaning but take the place of an adjective in a sentence. One of their examples: horse race.
So my question is this: Is there a word which describes or defines words such as these exactly? It would have a definition like this:
<mystery word> noun
- A word which itself may function as various parts of grammar without changing spelling or meaning.
- A word which has reached such widespread usage that it has definitions or meanings as a noun, verb, adjective, and/or adverb, all of which have the same origin or root word.
- A word that is a homonym of itself.
I have thought of and dismissed homonym, homograph, homophone etc. because they stipulate variously that the spelling, pronunciation or both are the same but differ in meaning and/or origin. I'm specifically looking for words that sound and are spelled the same and also have the same (or very similar) meaning and origin.
Excellent examples from the quiz I linked (spoiler alert):
- I have a sore sore.
- That mammoth is mammoth!
- I've never told anyone the combination, so my safe is still safe.
